A device for shielding and/or cooling electronic components

Abstract: The present invention relates to a device for shielding and/or cooling an electronic component mounted on a circuit board or the like. According to the invention, the device comprises a metal frame (2) which is mounted on the circuit board so as to surround the electronic component (1), and a metal cooling plate (3) which fits into the frame (2). The frame is provided along those edges thereof which lie distal to the circuit board with resilient contact means (5) which create electric contact between the plate (3) and the frame (2) and press the cooling plate (3) against the component (1) so as to achieve good thermal transmission between component and cooling plate.

Description: TECHNICAL FIELD The present invention relates to a device for shielding and/or cooling an electronic component mounted on a printed circuit board or the like; see for example DE-C-3717009. BACKGROUND ART It is often necessary to shield electronic components against ambient electromagnetic radiation, in order to prevent such components being affected by external interference, and in order to prevent, in turn, radiation emitted by such components having a disturbing influence on those parts of the equipment in which said components are fitted. Several different solutions have been proposed to this end. Many electronic components also generate heat when in use, and it is therefore necessary to cool such components to prevent them from being destroyed. Several different solutions have also been proposed to this end. The drawbacks with present-day devices is that they are intended either as a shielding medium or as a cooling medium, so that a device which is effective in shielding such components is not effective in cooling said components, whereas a device which is effective in cooling the components does not screen or shield the components satisfactorily. SUMMARY OF THE INVENTION The object of the present invention is thus to provide a device which will both shield and cool an electronic component in a satisfactory fashion. This object has been achieved with a device as defined in claim 1 which combines component shielding and component cooling in a two-part construction which comprises a metal frame that surrounds the component and a metal cooling plate which fits into the frame and includes cooling fins, wherein a number of resilient contact means create metallic contact between the plate and the frame and, at the same time, press the cooling plate against the electronic component so as to obtain good thermal transmission between the component and the plate. The device has acquired the characteristic features set forth in the following Claims. The advantage afforded by a device constructed in accordance with the invention is that one single device provides the dual function of shielding and cooling an electronic component. The device also functions equally as well in solely one of these aspects, i.e. is effective in performing solely a shielding or solely a cooling function. The invention will now be described in more detail with reference to an exemplifying embodiment thereof and also with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of one example of an electronic component and parts of the inventive device coacting therewith. Figure 2 is a perspective view and a sectional view of the device according to Figure 1 fitted over the component. BEST MODES OF CARRYING OUT THE INVENTION Figure 1 illustrates an electronic component 1 and a metal frame 2 and a metal cooling plate 3 which form parts of an inventive device. In the illustrated case, the electronic component 1 has the form of a multi-pole integrated circuit which emits heat in use, although the component may, of course, be any other heat-emitting component which is intended to be mounted on a circuit board or the like (not shown in the drawings). The size of the metal frame 2 is adapted to the size of the component 1, so as to enable the frame to be mounted on the circuit board while surrounding the component with the sides of the frame spaced slightly therefrom. The height of the frame 2 is adapted so that the frame will extend slightly above the component 1 when mounted on the circuit board, so as to enable the cooling plate 3 to be pressed against the component, as explained in more detail below. The metal frame 2 is provided along its bottom edges with connecting legs 4 which are intended to be received in corresponding holes in the circuit board or the like. The connecting legs 4 are also intended to connect the frame 2, and thus indirectly also the cooling plate 3, to an earthing surface in the circuit board, so as to connect the shielding device electrically to earth. The sides of the frame 2 are provided along their upper edges with resilient contact means 5, which have the form of tongues 6 clipped in the upper edges of said sides. The tongues 6 extend slightly above the upper edge of the frame and are bent inwardly towards the centre thereof. The outermost part 7 of respective tongues 6 is bent outwardly, as shown in Figure 1, and functions as a guide when the cooling plate 3 is fitted into the frame 2. The cooling plate 3 is comprised of a metal plate which is adapted to the size of the frame 2 and from which a number of cooling fins 8 have been clipped and folded upwards at a right angle. When fitting the cooling plate 3, the plate is guided into the frame 2 with the aid of the outermost parts 7 of the tongues 6, wherewith the contact means 5 spring outwards and then return and force the cooling plate 3 into abutment with the component 1 by virtue of the spring action exerted by their inwardly sloping sides, as illustrated in Figure 2. Because the cooling plate 3 fits precisely in the frame 2, and because the contact means 5 create metallic contact between the frame and the cooling plate, the component 1 is fully shielded by the frame and the plate when the plate is mounted in position. Because the cooling plate 3 is pressed against the component 1 by the contact means 5, there is also obtained good thermal transmission between component and cooling plate, and thus satisfactory cooling of the component, this cooling effect being enhanced by the cooling fins 8. It will be understood that the described and illustrated component shielding and cooling device merely represents an example of the invention, and that both the geometrical configuration and the number of connecting legs and the number of contact means can be varied in accordance with the configuration of the electronic component to be protected. The size and the number of the cooling fins can also be varied as required, and may even be omitted when the inventive device is intended solely to shield the component. It will also be understood that the invention is not restricted to the aforedescribed and illustrated exemplifying embodiment thereof and that this embodiment can be modified within the scope of the following Claims.

Claims: A device for shielding and/or cooling an electronic component mounted on a circuit board, the device including a metal frame (2) which is mounted on the circuit board so as to surround the electronic component (1), and a metal cooling plate (3) which fits into the frame (2), wherein the frame is provided with resilient contact means (5) along those edges thereof which lie distal to the circuit board, said contact means creating electric contact between the cooling plate (3) and the frame (2) and functioning to press the cooling plate (3) against the component (1) so as to obtain good thermal transmission between the component and the cooling plate. A device according to Claim 1, characterized in that the cooling plate (1) is provided with cooling fins (8) on that side thereof which lies distal to the component (1). A device according to Claim 1, characterized in that the contact means (5) are comprised of tongues (6) which have been clipped downwardly to some extent in the edges of the frame (2) and which are folded inwards and extend slightly above the upper edge of said frame. A device according to Claim 1, characterized in that the outermost parts (7) of the tongues (6) are folded outwards to form cooling plate guides when inserting the cooling plate into the frame. A device according to Claim 1, characterized in that the frame (2) is provided with connecting legs (4) for fitting the frame into corresponding holes in the circuit board and for connecting the frame to an earthing surface provided in the circuit board.

Inventors: PETTERSSON SVEN YNGVE, SCHNEIDER GEORG ADELBERT, PETTERSSON, SVEN YNGVE, SCHNEIDER, GEORG ADELBERT
Applicants: ERICSSON TELEFON AB L M, TELEFONAKTIEBOLAGET LM ERICSSON
Application year: 1994
Main classification: H05K7
IPC codes: H05K9, H01L23